... by replacing invalid bytes with the REPLACEMENT CHARACTER U+FFFD
This is better than:
- discarding the whole message, since the user would not see it...
- removing invalid bytes, since the user would not see their presence,
- converting the encoding (this is actually not possible).
Contrary to its documentation, strings.ToValidUTF8 doesn't copy the
string if it's valid UTF-8:
<https://golang.org/src/strings/strings.go?s=15815:15861#L623>
This panic happens when sending history to a multi-upstream client.
sendNetworkHistory is called on each network, but dc.network is nil.
Closes: https://todo.sr.ht/~emersion/soju/93
Instead, always read chat history from logs. Unify the implicit chat
history (pushing history to clients) and explicit chat history
(via the CHATHISTORY command).
Instead of keeping track of ring buffer cursors for each client, use
message IDs.
If necessary, the ring buffer could be re-introduced behind a
common MessageStore interface (could be useful when on-disk logs are
disabled).
References: https://todo.sr.ht/~emersion/soju/80
For now, these can be used as cursors in the logs. Future patches will
introduce functions that perform log queries with message IDs.
The IDs are state-less tokens containing all the required information to
refer to an on-disk log line: network name, entity name, date and byte
offset. The byte offset doesn't need to point to the first byte of the
line, any byte will do (note, this makes it so message IDs aren't
necessarily unique, we may want to change that in the future).
These internal message IDs are not exposed to clients because we don't
support upstream message IDs yet.
Keep the ring buffer alive even if all clients are connected. Keep the
ID of the latest delivered message even for online clients.
As-is, this is a net downgrade: memory usage increases because ring
buffers aren't free'd anymore. However upcoming commits will replace the
ring buffer with log files. This change makes reading from log files
easier.
For now it's just a new field that'll be useful to generate user ident
strings. It uses the SQLite implicit rowid column. In the future the DB
interface will need to be updated to use user IDs instead of usernames.
This defers TLS handshake until the first read or write operation. This
allows the upcoming identd server to register the connection before the
TLS handshake is complete, and is necessary because some IRC servers
send an ident request before that.
This allows to set the list of IPs allowed to act as a proxy. This is
only used for WebSockets right now, but will be expanded to TCP as well
once the PROXY protocol is supported.
When Unix socket support will be added for listeners, unix:// will be
ambiguous. It won't be clear whether to setup an IRC server, or some
other kind of server (e.g. identd).
unix:// is still recognized to avoid breaking existing DBs.
